Packets are transmitted from a server to a network after packet processing is performed by a network interface card (NIC) which the server has. Accordingly, the transmission rate of packets output to the network does not exceed a band limitation which is based on the processing capabilities of the NIC.
There are cases where multiple NICs are installed in a server and used at the same time, to realize a transmission rate exceeding the band limitation of a single NIC. In this case, bandwidth corresponding to the number of NICs used at the same time may be realized. If a transmission rate exceeding the processing capabilities of the multiple NICs already provided to the server is to be realized, a new NIC server is added.
Now, there is known a technique to virtualize NICs, as part of a technique to virtualize resources of information processing devices. In a case of virtualizing a NIC, a NIC does not have to be installed in the server. The server is coupled to a NIC virtualization device including multiple NICs, and switches to transfer packets to the NICs. The server outputs packets to the NIC virtualization device, specifying identification Nos. for assigned NICs out of the multiple NICs. The NIC virtualization device transfers packets to the corresponding NICs out of the multiple NICs, in accordance with the identification Nos. The NICs within the NIC virtualization device process the packets, and transmit the packets to the network.
Thus, the NIC virtualization device allows a server to user multiple NICs without physically installing more NICs to the server. Also, if a server has NICs installed, other servers will not be able to use these NICs even if there is excess processing capability. On the other hand, if there is excess in processing capability of NICs of a NIC virtualization device that are assigned to a certain server, these NICs may be also assigned to another server as well, and used in common.
There is known a technique where bypass circuits are installed between routers, usage rights are set so as to be restricted to transmission between particular terminal devices based on user contract, and router tables in the routers are rewritten so that data packets are transmitted between the particular terminal devices of which usage rights have been set via the bypass circuits.
An example of the related art is described in Japanese Laid-open Patent Publication No. 2003-218910.